As long as you can get the Rust code to compile it's about the same speed. The issue is that rustc is only available on limited platforms (and indeed lack of rustc has killed off entire hardware architectures in popular distros in a bit of tail wagging the dog), rustc changes in breaking ways (adding new features) every 3 months, current rust culture is all bleeding edge types so any rust code you encounter in the wild will require curl rust.up | sh rather than being able to use the 1 year old rust toolchain from your repos.
What good is speed if you cannot compile? c has both. Maybe in another decade rust will have settled down but now wrangling all the incompatible rust versions makes c the far better option. And no, setting cargo versions doesn't fix this. It's not something you'd run into writing rust code within a company but it's definitely something you run into trying to compile other people's rust code.
I've never run into this issue in the wild. It sounds like a hypothetical. Upgrading your Rust toolchain is ridiculously easy, and using a year old outdated toolchain is more or less a philosophical hang up than a technical one.
It's not a hypothetical. I was put off the entire language after it happened to me three times in a row with unrelated Rust written software. This was 1 month after Debian 12 was released (June 10, 2023) and I was running the brand new Debian 12 with rustc 1.63.0 from August 11, 2022. I ran into it with some web serial spidering and epub creation rust software (rust-wildbow-scraper). I ran into with a software defined radio spectrogram visualizer (plotsweep); I actually knew the author from IRC and he was able to edit it to not use bleeding edge rustc features and I managed to compile it. I can't recall the third. In the years since when I've stepped my toes into the "compile random rust programs with repo rust toolchain" and it's been the same.
But as you can see from my specific examples and dates: this is not a hypothetical. rust developer culture basically only writes for latest, having a 1 year old rustc is definitely not enough, and yes, installing compilers from a random website (curl site|sh) instead of my distro's repos is a problem.
Just because it hasn't happened to you doesn't mean it isn't a problem. Rust is a rolling release only compiler.
No, it's not. Your own misunderstandings of rust stable vs nightly and editions and using an unofficial installation method for a toolchain are not Rust's shortcomings. Sorry.
Ah, I see you are confused. I am claiming that rust is only for rolling distros because of it's needs for it's unique "official installation method" because of rapid addition of features making rustc need to be upgraded constantly. These facts are not in dispute though one's appreciation of the consequences apparently is.
What good is speed if you cannot compile? c has both. Maybe in another decade rust will have settled down but now wrangling all the incompatible rust versions makes c the far better option. And no, setting cargo versions doesn't fix this. It's not something you'd run into writing rust code within a company but it's definitely something you run into trying to compile other people's rust code.